CELKO (10/2/2012)
NO! We hate UDFs; they are not declarative, do not optimize and stink of 1950's FORTRAN. SQL is declarative and uses tables! This is a huge change in your mindset.
I don't know what you think declarative means, but the function that the OP is considering most certainly IS declarative in the sense the term is used by computer scientists and mathematicians, which is probably the only sense in which it should be used in a forum about T-SQL.
Tom